foam or milk foam 参考文献: 如何手工打制奶泡 How to froth with the finest Frothing (or foaming) milk properly is essential for creating a genuine espresso drink, like a cappuccino or macchiato. I can’t tell you how many times a glassy-eyed bandana-clad teenager has served me up a cappuccino with flat foam on top. Indeed, there is no sense in even distinguishing between a cappuccino and a latte if the foam is absent or corrupted. 全文在